In enzymology, a secondary-alcohol oxidase () is an enzyme that catalyzes the chemical reaction
Thus, the two substrates of this enzyme are secondary alcohol and O<sub>2</sub>, whereas its two products are ketone and H<sub>2</sub>O<sub>2</sub>.
This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with oxygen as acceptor. The systematic name of this enzyme class is secondary-alcohol:oxygen oxidoreductase. Other names in common use include polyvinyl alcohol oxidase, and secondary alcohol oxidase.